I measured the tracks, rollers, and drive gears and with that information designed the undercarriage layout. I will be manufacturing the idler/tensioner wheels fore and aft in the undercarriage assembly myself rather than buying them. Next I need to design some retainer plates for the undercarriage and then start ordering steel and cutting. I updated the track drive design too. I think I am going to go back to 1:1 drive on the motor/drive shaft connection since I probably don't need a top speed of 9 mph on this thing and would like the additional torque for pushing/pulling power.